[Show abstract][Hide abstract] ABSTRACT: Device-related complications in the thoracic aorta are partly due to the unavoidable proximal angulation and increased flow-related forces. The present study evaluated the incidence, predictors, and outcome of the complication of infolding with the GORE TAG thoracic endoprosthesis (TAG device) to better understand the factors that might help predict these events.
We reviewed all complaints reported to W. L. Gore and Associates (Flagstaff, Ariz) related to device infolding after the use of the GORE TAG device on or before December 2008. Events related to device infolding were evaluated. Reporting physicians and local company representatives were contacted, when necessary, to assemble all available imaging, data, and outcomes related to these case reports. When available, computed tomography images were reviewed to confirm aortic landing zone diameters, which were subsequently compared with the implanted device size.
From 1998 through December 2008, device infolding was reported in 139 patients (mean age, 40 ± 17 years; 73.4% men) from 33,289 device implants (reported incidence, 0.4%). Events were noted in implants for trauma (60%), dissection (19%), aneurysm (10%), and other (9%) and unknown (2%) etiologies. In 77 patients with available imaging, the average minimum aortic diameter was 21.4 ± 4.4 mm. The mean device diameter was 28.5 ± 3.5 mm, with an average oversizing of nearly 33%. Of reported patients, 51% were asymptomatic, with the diagnosis being made on routine chest imaging. Time to diagnosis was 76 ± 222 days (median, 9.5 days). Only 16 patients received no intervention after the diagnosis of device infolding, all of whom were asymptomatic. The other 123 patients underwent 135 interventions. Of these, 30 patients (24%) underwent open surgical conversion and complete or partial endograft removal. The other interventions included a variety of endovascular techniques, such as large balloon-expandable stent(s) in 40%, relining with additional endograft(s) in 31%, and repeat ballooning in seven patients. Ten patients died after device infolding, all after one or more attempts to repair the infolded device: five died of symptoms related to the infolding and five secondary to the intervention undertaken to correct the device infolding.
TAG device infolding appears to be an infrequent event, primarily occurring in young trauma patients secondary to excessive oversizing and severe proximal aortic angulation. However, there clearly exists a need for devices that treat such patients. As a result, future device designs should consider the compression failure mode when being designed in order to help prevent such events.
Full-text · Article · Dec 2011 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
[Show abstract][Hide abstract] ABSTRACT: Chronic cerebrospinal venous insufficiency (CCSVI) is a term used to describe impaired venous drainage from the central nervous system (CNS) caused by abnormalities in anatomy and flow affecting the extracranial veins. Recently, it has been proposed that CCSVI may contribute to the pathogenesis of multiple sclerosis (MS). It is hypothesized that venous obstruction results in abnormal flow that promotes inflammation at the blood-brain barrier and that this triggers a process marked by a disturbance of homeostasis within the CNS that leads to demyelination and neurodegeneration. The venous abnormalities of CCSVI are often diagnosed by ultrasound or magnetic resonance venography, however the prevalence of CCSVI detailed in groups of MS patients and patients without MS varies widely in published reports. Increased standardization of diagnostic studies to evaluate both anatomical and physiological findings associated with CCSVI is needed. The purpose of this article is to provide a background to understand the development of the theory of CCSVI and to frame the relevant issues regarding its diagnosis and relationship to the pathogenesis of MS.
No preview · Article · Oct 2011 · Functional neurology
[Show abstract][Hide abstract] ABSTRACT: To report a prospective, single-arm, multicenter clinical study evaluating the Zilver PTX drug-eluting stent for treating the above-the-knee femoropopliteal segment (NCT01094678; http://www.clinicaltrials.gov ).
The Zilver PTX drug-eluting stent is a self-expanding nitinol stent with a polymer-free paclitaxel coating. Patients with symptomatic (Rutherford category 2-6) de novo or restenotic lesions (including in-stent stenosis) of the above-the-knee femoropopliteal segment were eligible for enrollment. Between April 2006 and June 2008, 787 patients (578 men; mean age 66.6±9.5 years) were enrolled at 30 international sites.
Nine hundred lesions (24.3% restenotic lesions of which 59.4% were in-stent stenoses) were treated with 1722 Zilver PTX stents; the mean lesion length was 99.5±82.1 mm. The 12-month Kaplan-Meier estimates included an 89.0% event-free survival rate, an 86.2% primary patency rate, and a 90.5% rate of freedom from target lesion revascularization. There were no paclitaxel-related adverse events reported. The 12-month stent fracture rate was 1.5%. The ankle-brachial index, Rutherford score, and walking distance/speed scores significantly improved (p<0.001) from baseline to 12 months.
These results indicate that the Zilver PTX drug-eluting stent is safe for treatment of patients with de novo and restenotic lesions of the above-the-knee femoropopliteal segment. At 1 year, the overall anatomical and clinical effectiveness results suggest that this stent is a promising endovascular therapy.
No preview · Article · Oct 2011 · Journal of Endovascular Therapy
[Show abstract][Hide abstract] ABSTRACT: Sustained benefits of drug-eluting stents in femoropopliteal arteries have not been demonstrated. This prospective, multinational, randomized study was designed to compare the 12-month safety and effectiveness of a polymer-free, paclitaxel-coated nitinol drug-eluting stent (DES) with percutaneous transluminal angioplasty (PTA) and provisional bare metal stent (BMS) placement in patients with femoropopliteal peripheral artery disease.
Patients were randomly assigned to primary DES implantation (n=236) or PTA (n=238). Demographics and lesion characteristics were similar between groups (eg, average lesion length, approximately 65±40 mm). One hundred twenty patients had acute PTA failure and underwent secondary random assignment to provisional DES (n=61) or BMS (n=59). Primary end points were the 12-month rates of event-free survival and patency in the primary DES and PTA groups. Compared with the PTA group, the primary DES group exhibited superior 12-month event-free survival (90.4% versus 82.6%; P=0.004) and primary patency (83.1% versus 32.8%; P<0.001), satisfying the primary hypotheses. In the secondary evaluations, (1) the primary DES group exhibited superior clinical benefit compared with the PTA group (88.3% versus 75.8%; P<0.001), (2) the provisional DES group exhibited superior primary patency (89.9% versus 73.0%; P=0.01) and superior clinical benefit (90.5% and 72.3%, P=0.009) compared with the provisional BMS group, and (3) the stent fracture rate (both DES and BMS) was 0.9% (4/457).
Femoropopliteal peripheral artery disease treatment with the paclitaxel-eluting stent was associated with superior 12-month outcomes compared with PTA and provisional BMS placement.
[Show abstract][Hide abstract] ABSTRACT: The committee came to the general consensus that the mechanisms for evaluating patients with MS for jugular and azygous venous compromise and the value of treating these lesions with angioplasty warrant careful, well designed additional study. The committee believed the specific parameters needed for a large-scale, pivotal multicenter trial were not necessarily available at this time, but that these types of trials are the mandatory goal for study of CCSVI. Prospective safety and efficacy trials should be conducted in well defined and potentially smaller controlled populations under institutional review board approval. In addition, it is critical to support and continue the basic science work under way to better understand the relationship between venous stenoses and hypertension and the subsequent contribution of CCSVI to patients with MS. Animal models will likely prove useful, though inflammatory mediators may be assessed with serum sampling in the context of human trials. There will be many practitioners who will offer endovascular therapy to patients with MS in advance of the availability of definitive peer-reviewed data in support of that practice. It was the general hope of the committee that this work would lead to additional peer-reviewed studies generating data that clarify the role in MS of treating venous disease with angioplasty and possibly stent placement and the potential adverse events associated with these interventions (65). If additional studies confirm the initial reports in favor of CCSVI diagnosis and treatment, and appropriate study cohorts and standardized procedural technique and reporting are developed, it will be appropriate to pursue prospective multicenter trials. Enrollment in these trials will require the following: (i) confirmation of the diagnosis of MS based on currently accepted criteria; (ii) assessment of disease activity with conventional MR imaging; (iii) determination of clinical and functional status; (iv) listing of previous treatment for MS or other significant medical issues; (v) noninvasive screening documentation of venous disease with US and/or MR imaging/venography; and (vi) catheter-based venographic documentation of venous stenoses. Randomization against catheter venography without angioplasty would be required, with blinding of research personnel and examining neurologists. The potential role of stents would emerge from discussions of trial design. Imaging follow-up and clinical assessments might occur at 3, 6, 9, and 12 months after treatment, with a crossover permissible after a period yet to be defined. This type of study defines an ultimate goal in determining the contributory role of CCSVI and catheter-based interventions in patients affected with MS.
Full-text · Article · May 2011 · Journal of vascular and interventional radiology: JVIR
[Show abstract][Hide abstract] ABSTRACT: The Society for Vascular Surgery Outcomes Committee, including ad hoc members from Society of Thoracic Surgeons, American Association of Thoracic Surgery, and Society for Interventional Radiology, collected outcomes of patients with traumatic thoracic aortic transections treated with endovascular grafts. Results through 1 year of follow-up are reported.
Data from five physician-sponsored investigational device exemption clinical trials from 2000 to 2008 were entered using standardized forms and definitions. Adverse events were reported early (≤30 days) and late (>30 days) by body system. Major adverse events included one or more of the following: death, stroke, myocardial infarction, renal failure, respiratory failure, paralysis, or bowel ischemia.
There were 60 symptomatic patients (68.3% men; mean age, 46 years) with traumatic aortic transections, of which 97% were due to a motor vehicle accident and 3% were related to other blunt trauma. The average total injury severity score was 39, most with involvement of the chest and abdomen. The average surgical time was 125 minutes. The mean hospital length of stay was 17 days. Associated procedures for the management of nonaortic injuries occurred in 51.7%. All-cause mortality was 9.1% at 30 days and 14.4% at 1 year. One or more major adverse events occurred in 23.3% of the patients, major adverse events occurred early in 20.0% and late in 3.6%. Death accounted for 41.7% of the early and all of the late major adverse events. Early adverse events included 16.7% pulmonary, 13.3% neurologic, and 11.7% vascular complications. Late adverse events included one patient (1.8%) with pulmonary failure and one patient (1.8%) who died of an unknown cause.
One-year results of endograft placement for the management of patients with traumatic aortic injury are acceptable. Most cases treated were due to motor vehicle accident and associated with multiple coexisting injuries. Approximately three-quarters of the deaths occurred ≤30 days, indicating the acute severity of the condition. Although the relatively low rates of adverse and major adverse events are consistent with what is anticipated in an otherwise healthy population, future device and procedural developments may facilitate improved outcomes in the future.
Full-text · Article · Apr 2011 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
[Show abstract][Hide abstract] ABSTRACT: To evaluate the pharmacokinetics and safety of the Zilver PTX Drug-Eluting Stent (Cook Medical, Bloomington, Indiana) in a normal porcine artery model.
Pharmacokinetic analyses were performed using 18 pigs, each implanted with four paclitaxel-coated stents. Paclitaxel remaining on the stents, delivered locally (to artery wall), regionally (to adjacent and downstream muscle), and systemically (to plasma), was determined at various times through 56 days. For safety evaluation, local, regional, and systemic responses were grossly and histologically assessed at 1 month, 3 months, and 6 months in 21 additional pigs and compared with the responses to bare metal stents in 21 separate pigs.
Stents delivered approximately 95% of the total paclitaxel within 24 hours after deployment. Nonetheless, there were sustained paclitaxel levels in the artery wall through 56 days, maintained at approximately 20% of the peak level through 14 days. Very little paclitaxel was distributed regionally or systemically, becoming undetectable in plasma at 10 hours. Complete necropsy, hematology, and serum chemistry revealed no adverse effects associated with the paclitaxel-coated stents. Within 3 months, vessels with both paclitaxel-coated and bare metal stents showed comparable, complete healing.
The Zilver PTX stent appears to be safe, achieves sustained paclitaxel levels in the artery wall, and shows complete vessel healing comparable to bare metal stents within 3 months.
No preview · Article · Mar 2011 · Journal of vascular and interventional radiology: JVIR
[Show abstract][Hide abstract] ABSTRACT: This study analyzed 1-year outcome after thoracic endovascular aortic repair (TEVAR) in patients with complicated type B aortic dissection (cTBAoD) who had rupture or malperfusion and symptom onset ≤14 days (acute), 15 to 30 days (subacute), and 31 to 90 days (chronic) until required intervention. The main focus of this report is primarily on the acute cohort.
Clinical data were systematically collected from five physician-sponsored investigational device exemption (IDE) clinical trials between 2000 and 2008 using standardized definitions and forms. Adverse events were reported early (≤30 days) and late (>30 days) by body system. Major adverse events included death, stroke, myocardial infarction, renal failure, respiratory failure, paralysis, and bowel ischemia.
There were 99 cTBAoD patients: 85 were acute, 11 were subacute, and 3 were chronic. Among the acute patients, 31.8% had rupture and 71.8% had malperfusion, including 55.7% lower extremity, 36.1% renal, 19.7% visceral, 8.2% other, and 3.3% spinal cord (patients may have more than one source). Rupture and malperfusion were both reported for three acute patients. Additional findings for the acute cohort included pain (76.5%), hypertension (43.5%), and bleeding (8.2%); comorbidities included hypertension (83.5%), current/past smoking history (69.8%), and diabetes (12.9%). The main focus of this analysis was the acute cohort (n = 85). Age averaged 59 years (72.9% male). Early adverse events included pulmonary (36.5%), vascular (28.2%), renal (25.9%), and neurologic (23.5%). Early major adverse events occurred in 37.6% of patients, including death (10.6%), stroke (9.4%), renal failure (9.4%), and paralysis (9.4%); late adverse events included vascular (15.8%), cardiac (10.5%), gastrointestinal (6.6%), and hemorrhage (5.3%). The point-estimate mortality rate was 10.8 (95% confidence interval [CI], 4.1-17.5) at 30 days and 29.4 (95% CI, 18.4-40.4) at 1 year, when 34 patients remained at risk.
Emergency TEVAR for patients with cTBAoD (malperfusion or rupture) provided acceptable mortality and morbidity results out to 1 year. Manufacturers can use this 30-day mortality point-estimate of 10.8 (95% CI, 4.1-17.5) for the acute cohort to establish a performance goal for use in single-arm commercial IDE trials if the Food and Drug Administration and other regulatory bodies concur.
Full-text · Article · Feb 2011 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
[Show abstract][Hide abstract] ABSTRACT: Considerations in rational designs of CPP-based transcutaneous delivery systems are described. Impact of design considerations of nonclinical and clinical results are presented in detail.
No preview · Article · Jan 2011 · Methods in molecular biology (Clifton, N.J.)
[Show abstract][Hide abstract] ABSTRACT: Carotid atherosclerotic plaque rupture is thought to cause transient ischemic attack (TIA) and ischemic stroke (IS). Pathological hallmarks of these plaques have been identified through observational studies. Although generally accepted, the relationship between cerebral thromboembolism and in situ atherosclerotic plaque morphology has never been directly observed noninvasively in the acute setting.
Consecutive acutely symptomatic patients referred for stroke protocol magnetic resonance imaging/angiography underwent additional T1- and T2-weighted carotid bifurcation imaging with the use of a 3-dimensional technique with blood signal suppression. Two blinded reviewers performed plaque gradings according to the American Heart Association classification system. Discharge outcomes and brain magnetic resonance imaging results were obtained. Image quality for plaque characterization was adequate in 86 of 106 patients (81%). Eight TIA/IS patients with noncarotid pathogenesis were excluded, yielding 78 study patients (38 men and 40 women with a mean age of 64.3 years, SD 14.7) with 156 paired watershed vessel/cerebral hemisphere observations. Thirty-seven patients had 40 TIA/IS events. There was a significant association between type VI plaque (demonstrating cap rupture, hemorrhage, and/or thrombosis) and ipsilateral TIA/IS (P<0.001). A multiple logistic regression model including standard Framingham risk factors and type VI plaque was constructed. Type VI plaque was the dominant outcome-associated observation achieving significance (P<0.0001; odds ratio, 11.66; 95% confidence interval, 5.31 to 25.60).
In situ type VI carotid bifurcation region plaque identified by magnetic resonance imaging is associated with ipsilateral acute TIA/IS as an independent identifier of events, thereby supporting the dominant disease pathophysiology.
[Show abstract][Hide abstract] ABSTRACT: To review an experience with the Amplatzer vascular plug (AVP) for prevention of type II endoleaks during endovascular aneurysm repair (EVAR) of thoracic and thoracoabdominal aneurysms.
Retrospective review was undertaken of 14 patients undergoing transcatheter occlusion of the left subclavian (n = 12) or celiac artery (n = 2) with the AVP as part of EVAR of thoracic and thoracoabdominal aneurysms at a single institution. Procedural criteria evaluated were success at target vessel occlusion, the number of AVPs used, use of adjunctive embolization devices, and embolization-related ischemic end-organ events. Follow-up imaging criteria included evaluation of persistent target vessel occlusion, evidence of device migration, and the presence and characterization of endoleak secondary to AVP failure.
Complete target vessel occlusion was documented for all cases. In six cases, more than one AVP was placed, with an average of 1.5 devices per patient. In two cases, adjunctive coils were placed. Computed tomographic or magnetic resonance angiography follow-up was available for all patients (mean follow-up, 419 days; range 28-930 d). No case showed evidence of device migration or type II endoleak resulting from AVP failure. There was a single instance of left subclavian artery recanalization without type II endoleak. There were no embolization-related ischemic end-organ events.
Transcatheter arterial occlusion of the subclavian and celiac arteries with the AVP is a valuable adjunct to endografting in cases in which side branch embolization is necessary to extend the landing zone.
No preview · Article · Oct 2010 · Journal of vascular and interventional radiology: JVIR
[Show abstract][Hide abstract] ABSTRACT: To determine the clinical importance of the bird-beak configuration after thoracic endovascular aortic repair (TEVAR).
The institutional review board approved this retrospective study and waived the requirement to obtain informed consent from patients. Sixty-four patients (40 men, 24 women; mean age, 64 years) who underwent TEVAR were evaluated. The treated diseases included dissection (n = 29), degenerative aneurysm (n = 13), acute traumatic transection (n = 8), pseudoaneurysm (n = 4), penetrating aortic ulcer (n = 6), intramural hematoma (n = 2), and mycotic aneurysm (n = 2). Bird-beak configuration, defined as the incomplete apposition of the proximal endograft with a wedge-shaped gap between the device and the aortic wall, was assessed with postprocedural CT angiography. The presence and length of the bird-beak configuration were compared with the formation of endoleaks and adverse clinical events.
Endoleaks were detected in 26 (40%) of the 64 patients, including 14 with type Ia endoleak formation, one with type Ib endoleak formation, six with type II endoleak formation (from the left subclavian artery), two with type IIo endoleak formation (from other arteries), and three with type III endoleak formation. Bird-beak configuration was observed in 28 (44%) of 64 patients and correlated significantly with the risk of developing a type Ia or IIa endoleak (P < .01). Mean bird-beak length was significantly longer (P < .01) in patients with a type Ia or II endoleak (mean length, 14.3 and 13.9 mm, respectively) than in patients without endoleaks (mean length, 8.4 mm). Adverse events included early aortic-related death in three patients, additional treatment for endoleak in eight patients, and stent-graft collapse or infolding in six patients.
Detection of bird-beak configuration is helpful in the prediction of adverse clinical events after TEVAR.
[Show abstract][Hide abstract] ABSTRACT: This study evaluated the feasibility, efficacy, and outcome of endovascular therapy combined with immunosuppressive therapy for aortic pseudoaneurysms in patients with Behçet disease.
Between April 2002 and April 2008, 12 pseudoaneurysms (9 involving the intrarenal abdominal aorta, 1 at the suprarenal level, and 2 in the supraceliac aorta) in nine men and one woman with Behçet disease were evaluated at Peking Union Medical Center (PUMC). Three bifurcated stent grafts and seven tubular stent grafts, including two fenestrated stent grafts, were deployed. All 10 patients received immunosuppressive therapy after the implant procedure.
All patients underwent successful endovascular therapy without major complications during the 30 days immediately after the procedure. One patient with two aneurysms had treatment of only the larger infrarenal symptomatic aneurysm, but the smaller suprarenal pseudoaneurysm was not addressed because of its proximity to mesenteric branches. During a mean follow-up of 25.8 months (range, 6-50 months), nine aneurysms resolved completely in eight patients. The only untreated aneurysm, which coexisted with a treated lesion, remained stable under imaging observation. Three aneurysms recurred in two patients. At 6 months, one patient presented with a new aneurysm at the femoral artery access site for stent graft introduction and another formed at the proximal margin of the stent graft. Despite medical advice, he had stopped immunotherapy. He died from aneurysm rupture 8 months after stent deployment. Another patient with recurrent aneurysmal disease at the distal margin of the primary stent was successfully treated with an additional stent graft. These two were the only patients who did not adhere to taking immunosuppressant medicine after discharge.
Endovascular stent graft placement combined with immunosuppressive treatment for aortic pseudoaneurysms in Behçet disease is a feasible and effective management option. Long-term immunosuppressive therapy after endovascular repair is important to limit pseudoaneurysm recurrence.
Full-text · Article · Sep 2009 · Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter
[Show abstract][Hide abstract] ABSTRACT: We sought to review the clinical sequelae and imaging manifestations of thoracic aortic endograft collapses and infoldings and to evaluate minimally invasive methods of repairing such collapses.
Two hundred twenty-one Gore endografts (Excluder, TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz) were deployed in 145 patients for treatment of pathologies including aneurysms and pseudoaneurysms, dissections, penetrating ulcers, transections, fistulae, mycotic aneurysms, and neoplastic invasions in 6 different prospective trials at a single institution from 1997 to 2007. Device collapses and infoldings were analyzed retrospectively, including review of anatomic parameters, pathologies treated, device sizing and selection, clinical sequelae, methods of repair, and outcome.
Six device collapses and infoldings were identified. Oversized devices placed into small-diameter aortas and imperfect proximal apposition to the lesser curvature were seen in all proximal collapses, affecting patients with transections and pseudoaneurysms. Infoldings in patients undergoing dissection represented incomplete initial expansion rather than delayed collapse. Delayed collapse occurred as many as 6 years after initial successful deployment, apparently as a result of changes in the aortic configuration from aneurysmal shrinkage. Clinical manifestations ranged from life-threatening ischemia to complete lack of symptoms. Collapses requiring therapy were remedied percutaneously by bare stenting or in one case by branch vessel embolization.
Use of oversized devices in small aortas carries a risk of device failure by collapse, which can occur immediately or after years of delay. When clinically indicated, percutaneous repair can be effectively performed.
No preview · Article · Sep 2009 · The Journal of thoracic and cardiovascular surgery